Stitch wrote:Assuming the A350-1000ULR's fuel capacity is raised to the 165,000 liters of the A350-900ULR, that is 129,500kg using Airbus' 0.7855kg per liter value from their ACAPs. That leaves 186,500kg for structure and payload at a 316,000kg TOW. If we're thinking a 30,000kg payload, then that leaves 156,500kg for structure. Based on claims about the A350-1000's Basic Empty Weight, I think ~157,000kg is quite (if not more than) sufficient to cover DOW.
Leeham.net projects the 777-8's OEW to be around 15,000kg higher than the A350-1000 when both are in a two-class configuration with similar seating. The 777-8 can tank more fuel volume than the A350-1000ULR (198,000 liters), but of course that extra fuel weighs more. At maximum fuel load (159,000 kg) and with a 175,000kg DOW that would leave only 17,000kg left for payload at the current 351,000kg TOW, but I expect (hope) the 777-8 doesn't need that much fuel for the mission.
If we assume the 777-8 needs a similar fuel load to the A350-1000 (and that may very well be an unsafe assumption), then the 777-8 looks nice at 45,000kg. And if Airbus needs to add ACTs to the A350-1000ULR to make the range, then her available payload weight (and cargo volume) would drop, as well. But the numbers still seem to favor the A350-1000 unless she needs a significant fuel load boost beyond 165,000 liters.
The 779 is 181,400 kg QEW and 77 m
The 77W is 167829 kg OEW and 74 m long, while the 77L is 145150 kg OEW and 64 m long. 22769 kg for 10 m, or 2277 kg / m
The 778 is 7 m shorter than the 779. At 2277 kg / m, the 778 will be 15939 kg less, or 165461 kg. Approximately.
But in any case, about 10000 kg less than what Leeham came up with.